Studies are being conducted to evaluate the effects of sera and plasma from AIDS patients on the growth and responsiveness of T cell lines and clones. Mixed leukocyte culture assays are also being used as a system in which to study suppressor factors from materials. As much as 70 percent suppression has been found from pooled AIDS plasma on the MLC response. Experiments are underway to determine any functional changes in B cell activation following cryopreservation of AIDS lymphocytes. Macrophage and null cell antibody directed cell mediated cytotoxicity are also being studied. Macrophage cultures have been established for the purpose of propagating and studying any potential AIDS agents. Biochemical and functional characterization of immune-complexes from AIDS patients sera are currently underway. Isolation of these complexes are being evaluated for viral content by DNA blotting and suppressor effects in the MLC assay. Other serological markers from AIDS patients which are currently being evaluated are B2 microglobulin and changes in isotype levels. Recently, helper to suppressor ratios of AIDS patients have been performed (for investigators in the Institute) using the FACS-Analyzer. In addition to routine screening, we are establishing normal parameters for use of the analyzer and methods for determining phenotypes of lymphocytes from normals and AIDS patients following cryopreservation. Using the FACS-II, two color parameter analysis, studies of normal and AIDS lymphocytes has also begun.